You two never actually met in person, correct? This is an awful lot of agony and analysis over someone you've never met. The guy behaved very poorly in the end. As to why? Who knows? But it seems to me that you were not that interested in him at first and not for a while. And then slowly, you started to show greater interest, yet there was a great delay between saying you want to meet up and actually trying to plan to meet up. It seems that's when he started to show less interest. He likely thought you were just stringing him along and behaved immaturely in the end. Yes, it's possible that he felt rejected.

But honestly, so much agony over someone you've never met in person before is too much wasted time. The guy behaved like a true a-hole in the end, and really, that's all you need to know at this point.